A New User-Friendly Sketch-Based Modeling Method Using Convolution Surfaces

Abstract

3d modeling systems are essential tools for creating3D content for virtual reality systems. They are powerfuland sophisticated computer applications with a steep learningcurve. When considering simple shape prototyping it is moreappropriate to use a software with a simpler and intuitiveuser interface. This paper proposes a new sketch-based modelingapproach relying on convolution surfaces that enablesthe user to specify 3d shapes of arbitrary topology andresolution from 2d hand-drawn sketches that are embeddedand manipulated in 3d space. To make this approach feasiblewe propose two innovations: the first one is an interactionmechanism to create, manipulate and assemble independent2d sketches embedded in 3d space relying only on simplerotations, translations and a ray casting step; the second oneis a new approach to fit the level set surfaces generated bythe convolution of skeleton primitives to the silhouette curvesspecified by the user. The proposed fitting combines a methodthat automatically computes weights for the convolutionoperation with a Stolte's blending function that controls theinfluence of each implicit functional components to the finalshape. We show via experiments and preliminary user teststhat our method permits the user to easily express his 3dconcepts by sketching and assembling 2d simple drawings intridimensional space.